1. Field of the Invention
The subject invention relates to electrochemical machining (ECM) apparatus and processes utilizing a pulsed-power supply.
2. Related Art
ECM apparatus and methods using pulsed power are well known in the related art. Typically, a pulse of electric power is transmitted to an electrode, through a gap of an electrolyte, to a workpiece. This process results in the erosion, or machining, of the workpiece.
An early example of this technology is seen in U.S. Pat. No. 3,607,689. The '689 patent discloses an ECM apparatus capable of providing a pulse of electric power. Triggering a silicon controller rectifier (SCR) to discharge a capacitor generates this pulse of electric power. The pulse of electric power has a maximum current of 300,000 amperes. However, due to the slow switching time of the SCR, the minimum pulse duration achieved by the apparatus is only one millisecond.
Another example of an ECM apparatus is revealed in U.S. Pat. No. 4,113,587. This ECM apparatus is capable of producing a pulse of electric power with a minimum duration of 10 microseconds. The pulse of electric power has a maximum current of 300 amperes/cm2. However, the ECM apparatus of the '587 patent cannot produce a pulse with a minimum duration of less than 10 microseconds and effectively provide an electric charge to an electrode and a workpiece to machine the workpiece.